MAGNETIC OBSERVATIONS. 
141 
OBSERVATIONS—Continued. 
Station, Camp 128, Rio Colorado ; latitude 34° 23' 10". 10 ; longitude 7 h. 3G m. 25. GGs. 
Needle, B. Date, February 21, 1854. Hour of beginning, 3 h. 15 rn. p. m.; hour of ending, 3 h. 30 m. p. m. 
Observer, Lieut. J. C. Ives, Topographical Engineers. 
O ' " 
f 72 25 
Needle vertical, face of circle north, reading of azimuth circle.-j 72 30 
( 72 30 
f 72 30 
Needle vertical, face of circle south, reading of azimuth circle.72 38 
( 72 32 
Reading of azimuth circle when plane of instrument is in the magnetic meridian... 72 30 50 
Reading of azimuth circle when plane of instrument is in the true meridian.. 86 38 39 
Approximate.magnetic declination...... 14 07 49 E. 
OBSERVATIONS FOR MAGNETIC INCLINATION AND INTENSITY—No. 4. 
Face of circle. 
Direct. 
Def. with wt. 2\ gr. 
Def. with wt. 3 gr. 
Def. towards 
the vertical. 
(1) 
Def. from the 
vertical. 
( 2 ) 
Tlier. 
Fahr. 
Def. towards 
the vertical. 
(1) 
Def. from the 
vertical. 
( 2 ) 
Thcr. 
Fall. 
East. 
West. 
o ' 
60 23 
60 27 
60 30 
60 28 
60 25 
60 21 
Means.. 
o ' " 
60 25 40 
Cor. for index error of needle... 
Deduced inclination. 
+ 8 48 
o ' " 
60 34 28 
Differences 
Half diff. or angles of deflection . 
Sum of means.. 
o ' 
94 28 
94 25 
94 25 
94 33 
94 30 
94 32 
o ' 
26 12 
26 15 
26 15 
2G 12 
26 05 
26 10 
o 
75 
75 
o ' 
102 32 
192 30 
102 40 
102 28 
102 30 
102 20 
o ' 
17 60 
17 58 
17 62 
17 50 
17 55 
17 50 
S (1) 
O 
94 
28 
50 ) 
o 
j (1) 
o 
102 
30 
00 ) 
! (2) 
26 
11 
30 j 
\ (2) 
17 
55 
50 j 
68 17 20 
84 34 10 
34 08 40 
42 17 05 
120 40 20 
60 20 10 
o ' 
120 25 50 
60 12 55 
o 
75 
o 
75 
Half sum — dip 
